App sideloading refers to the process of installing applications on a device from sources other than the official app store, such as Google Play or Apple's App Store. This practice is common on Android devices, where users may download APK files directly from the internet. While sideloading can provide access to apps not available in official stores, it also poses significant security risks. Apps from unofficial sources may not undergo the same security checks and can contain malware or spyware, potentially compromising user data and device integrity. Cybercriminals often exploit sideloading to distribute malicious software.